Self-cleaning punch



Oct. 24, 1950 R. L. GOEMAERE 2,526,741

SELF-CLEANING PUNCH Filed May 27, 1949 INVENTOR. 055 2; 1. 606440595Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to devices for removing material from work andparticularly to an improved self-cleaning punch for cutting sheetmaterial.

In operating upon sheet material such as cardboard trim panels and othersimilar kinds of sheet material, it has been the practice to use a punchfor cutting holes through the sheet material through which variouselements may be passed. Heretofore, the punching out devices employedfor such purposes have been rather small in size and slow in operationand required periodical removal of the device to clean out the severedportions of the sheet material therein. Where attempts have been made toout out larger sizes of openings in the sheet material, the punching outdevices clogged and slowed in use.

An important object of this invention is to provide an improvedself-cleaning punch which quickly and cleanly removes the cut out blanksof the sheet material and which will operate indefinitely and withoutthe necessity of periodically removing the punch to clean out the blankscollected therein. Another important object of the invention is toprovide a punch of this character which is provided with a leadingcutting edge for severing the sheet material and cutting a blanktherefrom and further provided with an interior secondary cutting edgewhich subdivides the cut out blanks so that they may be readilydischarged from the punch. A further important object of the inventionis to provide a punch of this character which is economical tomanufacture and easily installable for operation.

A self-cleaning punch constructed in accordance with this inventionpreferably comprises a one-piece member of generally cylindricalconstructure provided at the lowerend thereof with a cutting edge,usually circular in character, and a central passageway leading up fromthe cutting edge and dividing into two diverging passages through whichblanks cut out from the sheet material are passed. Within the interiorof the body there is provided a novel cutting edge extending preferablydiametrically to the circular cutting edge but recessed thereabove andlocated between the branching passages so that as the blanks commence topass therethrough they are severed into smaller sections. In thepreferred form of the invention the secondary cutting edge is located atthe juncture and forms the common meeting edge of the two passages.

Various other objects, advantages and meritorious features of theinvention will become more fully apparent from the followingspecification, appended claims and accompanying drawings, wherein:

Fig. l is a top plan view of a vertically reciprocating part of a punchpress illustrating the mounting of the self -cleaning punch therein andits relationship to the die-board in which it is secured,

Fig. 2 is a vertical cross sectional view through the punch pressmachine illustrating the position of the self-cleaning punch therein andthe two cutting edges thereof,

Fig. 3 is a vertical sectional view taken along line 33 of Fig. 1 andbeing 90 to that illus trated in Fig. 2, and

Fig. 4 is a fragmentary sectional-view similar to the central portion ofFig. 2 illustrating the self-cleaning punch in operation and the mannerin which the cut blanks are removed therefrom.

The apparatus in which the self-cleaning punch is located comprises afixed base support II] which is usually flat for receiving a sheet ofcardboard trim panel or other severable material l2. Surmounting thefixed support In is a vertical reciprocating body including a horizontalextending die-board I4 in which is fixed a selfcleaning punch generallyindicated at It constructed in accordance with this invention. Theself-cleaning punch'reciprocates jointly with the die-board l4 and thelower end thereof is brought into engagement with trim panel l2 forcutting a blank thereout. The die-board l4 and the punch l6 may besecured to the underside of any suitable type of reciprocating member,ram or other moving part of a punch press.

The body of the self-cleaning punch is preferably formed in one piece ofcast metal and has a general cylindrical formation. The lower end of thepunch body is provided with a circular cutting edge [8 which is adaptedto penetrate the trim material and cut out a circular blank therefrom.The interior of the body I6 is hollowfor part way above the cutting edgeI8 and forms a central vertical passage 20 extending to upwardlyapproximately mid-way between the upper and lower ends thereof. Thepassage 20 is divided at approximately the middle of the body into twodiverging branches 22-22 of corresponding shape and formation. Theselast two branching passages open out through the upper end portion ofthe body at the corner formed between the top face 24 thereof and thecircular side wall thereof. Opening out in this manner, the branchpassages leave a considerable area of the top face 24 for directengagement with the lower side of the reciprocating member or ram towhich the die-board It is secured.

The two passages 2222 each have a width in one dimension less than thediameter of the blank cut by the punch and the passage and normallyneither one of these branches would be able to take the circular blankcut out by the punch. To further subdivide the circular blanks cut outby the punch in order that these subdivided sections may pass throughthe branches 22-22, there is provided a second cutting medium. As shownin Fig. 2, the walls of the branch passages convergingly slope towardone another and join together to form a downwardly tapered centrallylocated boss terminating in an apex 26 extending across the mainpassage. The boss serves as a sturdy carrier or support for the secondcutting medium and as illustrated herein the common meeting edge orjuncture line 26 is utilized as the secondary or supplemental cuttingedge. This cutting edge, as shown in dotted outline in Fig. 3,preferably extends straight acros the circular larger passage 20 anddiametrically thereof so as to bisect the blanks cut out by the leadingedge l8. The subdividing or bisectin operation is shown in Fig. 4,wherein a stack of cut out blanks 28 from previous cutting operations isshown advancing upwardly through the punch and being severed by theinterior cutting edge 26. The subdivided sections of the circular blanksare fed upwardly through th branch passages 2222 and eventually aredischarged from the punch. To facilitate the discharge of the cutblanks, the die-board I4 is preferably shaped in the manner shown inFig. 1 to provide openings 30-30 on opposite sides of the punch press.As shown in Fig. 1, each branch passage 22 aligns with one of theopenings 30 so that as the cut blanks are accumulated they are forced bypressure of additional blanks out of the passage 22 and through theadjacent opening 39. The cut blanks will fall upon the platform !0 andmay be swept away at convenient times between th removal of one sheet I2and the replacement of a new sheet thereon.

There is associated with the self-cleanin punch a pair of resilientmembers 32-32 on opposite sides of the punch and corresponding in shapeand formation to one another. These resilient members are preferablycomposed of rubber and are secured at their upper ends by adhesion orotherwise to the under side of the dieboard M. These rubber elements areof such length as to project below the leading cutting edge I8 of thepunch as shown in Fig. 3. In operation of the device, these rubbermembers 32 are compressed by their engagement with the sheet material [2and contract as the cutting edge !8 pierces the sheet material. As thepunch is lifted from the cut material the members 3232 resilientlyexpand and force the sheetmaterial away from the punch.

Although the punch body illustrated herein is shown as cylindrical andprovided with a circular cutting edge [8, it is understood that thepunch body may be of an oval or a generally square 01 rectangularformation in order to cut oval, square or rectangularly shaped holes inthe sheet material [2.

What I claim is:

1. A self cleaning punch device comprising, in combination, a hollowbody interiorly shaped to form a main passage opening out through thebottom portion thereof and at least two branch passages communicatingwith the upper end of the main passage and extending upwardly andoutwardly away from one another and opening out through the side wall ofthe body adjacent to the upper end thereof, a continuous cutting edgesurrounding the bottom opening of the main passage and adapted to cutout blanks from sheet material upon which the punch operates and tosuccessively feed the cut out blanks into the main passage, a secondcutting edge located in said main passage adapted to sever the blanksreceived therein into smaller sections, a supporting memher for thepunch body secured to the upper portion thereof for joint movementtherewith, said supporting member being wider than the punch body andprovided with downwardly opening recesses aligning with the opened upperends of the branch passages to facilitate discharge of the severedsections of the blanks escaping therefrom.

2. A self cleaning punch comprising, in combination, a. hollow bodyhaving a substantially closed upper end forming a relatively flat topface and provided on the lower end with a continuous cutting edgeadapted to cut a blank out of sheet material upon which the punchoperates, said body being shaped interiorly to provide a main passageopening out through the lower end thereof through the area defined bythe cutting edge for receiving successive blanks cut by said edge andhaving a cross sectional area at least equal to that of the blank cutout of the sheet material, said main passage extending upwardly from thecutting edge and dividing interiorly of the body into at least twoupwardly and outwardly diverging subsidiary branch passages each havinga cross sectional area less than that of the main passage, the upperends of the branch passages opening out through the side wall of thebody immediately adjacent to the top face thereof, said branch passageshaving sloping walls converging together and forming a downwardlytapered boss in the central part of the body, a supplementary cuttingmedium carried by the boss and operable to sub-divide the blanks intosmaller sections, and a die-board extending fiush with the top face ofthe punch body and connected to the upper end thereof, said die-boardprovided with downwardly opening recesses aligning with the upper openedends of the branch passages to facilitate the escape of the severedsections of the blanks discharging therefrom.

3. A self cleaning punch comprising, in combination, a hollow bodyhaving a substantially closed upper end and provided on the lower endwith a continuous cutting edge adapted to cut a blank out of sheetmaterial upon which the punch operates, said body being interiorlyshaped to provide a vertically extending main passage opening outthrough the lower end of the body through the area defined by thecutting edge for receiving successive blanks cut by said edge, the crosssectional area of said main passage throughout its length being at leastequal to that of the blanks cut out of the sheet material upon which thepunch operates, a downwardly tapered boss in the upper end portion ofthe main passage and constituting an integral part of the body, said 5 6boss having sloping walls converging to an apex REFERENCES CITED on thelower end P and subfhvldmg the The following references are of record inthe upper portion of the main passage into at least file of this patent.two upwardly and outwardly inclined branch passages, said branchpassages communicating 5 UNITED STATES PATENTS at theirlower ends withthe main passage and Number Name D t opening out through the side wallof the body a 153,556 Fisher July 28, 1874 their upper ends and eachhaving a cross sec- 1,129,079 Donaldson Feb. 23, 1915 tional area lessthan that of the mai pa g 1,309,157 Stockman July 8, 1919 and asupplemental cutting medium carried on 10 1,321,896 Davis Nov. 18, 1919the lower apex end of the boss and operable to sub-divide the blanksreceived by the main passage into sections of a size to pass through thebranch passages.

RUSSELL L. GOEMAERE. 15

